The cock is filed/milled out a piece of mild steel 10cm x 5cm x 2,3cm and a lot more work than the lock plate. True up the block in the so everything is square and level. Paint with dykem. Place the cock on the block. Make sure the jaw is aligned square with the length of the block. Drill holes to lock it in place. The hole at the throat is 7mm, the axel hole 6mm and the at base of the neck 2,5mm. Place something under the base of the cock to keep it level.
Take 1,5mm drill and drill shallow “dots” around the outline of the cock.
This gives you a tracing of the cock.
I then did the mistake of drilling and cutting out the blank.
The neck was to skinny and the angle of the jaw to steep. I traced the blank to 1/16” brass sheet, corrected the mistakes and made a brass pattern. I should have made the brass pattern first, before starting on the steel. This could be done by gluing av piece of brass to a block of hard wood and mounting the cock on that.
Making the cock was a lot more trial and error than the lock plate and I ended up scraping my first two attempts. The rest of the description shows the final process I used.
1.Square up the block and draw file one face. It’s easier to see the scribed lines on a smooth surface. Scribe a line square to the long side of the block.
2.Glue the pattern to the block with the jaw lined up with the scribed line. Paint with dykem, scribe. Drill the 7mm throat hole, 6mm axel hole and the 2,5mm neck hole. Heat, remove pattern.
3.Next scribe these guide lines. The line to the left is the temporary shoulder line. The to the right is for drilling out the jaw.
4.Drilling 2mm holes through 23mm thick steel is a royal pain in the ass, even with cutting oil. After 40 holes the drill is dull, sticks the hole and snaps off. The hole needs to be cleared of chips every 2 -3mm. It pays to reduce the thickness of the block, whenever possible, before drilling out the outline. Turn the around and start milling out the part below the shoulder line down to 11mm. That gets rid of half the steel without messing up the scribed outline.
5.I made a pattern of the base of the cock, and in theory I could have milled away another 5mm from the face side of the block and used it to restore this part of the pattern. But I chicken out. I afraid it would not line up with the original scribed pattern. I chose to start drilling the out line.
As you can see, I did not drill the top of the jaw and the outline of the spine. I’ll explain why, when we get there.
6.Saw out the base, file it clean and square.
7.Keeping the rest of the block square makes it easier to mount level in the machine vice for milling. Reduce the base to its final thickness, 6mm.
8.Saw out the top right corner of the block.
9.Mill down to the level of the spine.
10. Mill out the top of the jaw and the shelf for the top jaw. This insures they are square each other.
11. Mill out the thickness of the spine. Remember to keep a tab at the top end blank. This is needed to keep the block level during milling and drilling. Do this on both sides of the block
12. Trace the original brass pattern to another piece of brass a make pattern for the spine only. The length of the rectangle at the base is the length of the jaw.
13. glue it on, paint with dykem, scrib , heat, and drill out.
14. Saw out the spine and the rest of the cock. File to the scribed line.
15. Drill and tap the hole for the top jaw screw while everything is still square. I used ¼-20.
16.Bevel the cheeks of the cock. On the frontside the bevel goes from the edge of the jaw the base of the cock. The backside is a bit tricky. The rear flat of the base is right in the middle of the cock. Measure the thickness of the base and transfer it to the shoulder. The cheek on the backside is filed for the edge of the jaw to this line. This keeps the neck symmetrical.
17.File out the jaw profile at round the jaw and work your way around the blank. Most of the work is done with a round file and a small half round file.
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18. Make the top jaw screw from a 10mm bolt.
19.Turn the shaft 6,5mm. Reduce the diameter in one cut from the end of the blank. This puts the pressure down the axis of blank and keeps the shaft straight. Don’t try many shallow cuts. That puts the force across the axis and bends the blank.
20.Cut the threads and turn the head. The neck is done with a chainsaw file. Round the head with files before parting the screw.
21.Make the top jaw from 6mm thick steel sheet stock. Drill a 6,5 mm hole about 3mm from each end, cut off the blank, shape one front corner. Glue it on a piece of masking tape and cut around the blank.
22.Peel off the tape and stick it on the other side of blank. You now have a pattern for the opposite corner. NB! To work the blank has to be perfectly square.
23.Soft solder to a bolt, to hold it in the vice.
24.Shape with half round and round files.
22. The finished cocks.
It took me 28 hours to get from the steel block to the finished cock.
I’m happy with the results. Using brass patterns insures reasonably identical parts.
The NeXT part to tackel will be the pan. Hope to post that in august.
Best regards
Rolf
